The safety of co-administration of recombinant zoster vaccine (Shingrix) and influenza vaccines in the elderly in VAERS during 2018-2024

Abstract

This post-marketing safety study evaluated the co-administration of recombinant zoster vaccine (RZV, Shingrix) and influenza vaccines (HD-IIV/aIIV/RIV) in adults aged ≥ 65 years using U.S. VAERS data (2018-2024). Among 791 adverse event (AE) reports analyzed via empirical Bayesian data mining and clinical review, 55 (6.9%) were serious, with non-serious AEs dominated by injection site reactions (65%), pyrexia (15.2%), and chills (13.4%). Serious AEs included asthenia (8.1%), pyrexia (8.1%), and Guillain-Barré syndrome (GBS, 6.4%); clinical review confirmed 7 Brighton-criteria GBS cases and one Bell's palsy. Data mining detected no new safety signals, and comparative analysis revealed that co-administration safety aligned with clinical trial profiles and monotherapy (influenza/RZV alone), showing no elevated risks. These findings support co-administration safety in older adults, advocating for community pharmacy-based delivery to optimize coverage. Limitations include VAERS' passive surveillance nature (underreporting, lack of denominator data), necessitating cautious interpretation and ongoing monitoring.

Keywords: Vaccine safety; adverse event; co-administration; influenza vaccine; recombinant zoster vaccine; surveillance.

Figure 1.

Most common MedDRA preferred terms following co-administration of RZV booster dose and influenza vaccines (n = 221), and a booster dose of RZV alone (n = 9,160).

Figure 2.

Adverse event risk signal identification: risk signal identification of local/systemic adverse reactions in non-serious reports across groups (combined control group and subgroup comparisons) (a, b); risk signal identification of local/systemic adverse reactions in serious reports across groups (combined control group and subgroup comparisons) (c, d); risk signal identification of specific adverse reactions in serious reports across groups (combined control group and subgroup comparisons) (e, f).